step(ps,umc2,tm(s,[ctxm(alpha_2_1_,ps,ip, (ip,ps), (ip,ps)),ctxm(alpha_2_1_,umc,ip, (ip,umc2), (ip,umc2))],pri(pc,[ctxm(alpha_2_1_,dot,s,i_s,c_s),pri(enc,[ctxm(alpha_2_1_,u,bsn,i_bsn,i_bsn),ctxm(alpha_2_1_,dot,s_umc, (i,s_umc), (c,s_umc))]),ctxm(alpha_2_1_,umc,dom, (dom,umc2), (dom,umc2))]))).
